The invention relates to guidance systems for missiles, particularly those launched from aircraft.
Many tactical missiles, after being launched from an aircraft, are required to fly a constant altitude, constant heading path in the cruise search mode. The missile is held to this path by an inertial system in which rate gyros provide the yaw, pitch, and roll angle references. These references must be properly aligned. Yaw or heading reference alignment can be provided by the launch aircraft with reasonable accuracy. However, the roll and pitch references, which must be aligned to the local vertical, can not be provided by launch aircraft attitude with sufficient accuracy. This is particularly true for the pitch reference because of the wide range of pitch attitudes employed by delivery aircraft. Prelaunch alignment of the roll and pitch references involves significant technical complexity and cost, which are not compatible with a basic missile design objective of simplicity. For maximum design and operational simplicity, it would be highly advantageous if the missile could execute its own alignment of the roll and pitch gyros after launch. It is the object of the invention to provide such alignment.